Photovoltaic (PV) panels and panel arrays are commonly used on residential and commercial roofs to generate electricity. Individual panels are typically secured to a roof using first, a set of roof penetration mounts each comprising a vertical post; second, a set of rails, or struts, that attach to the penetration mount posts; and third, a set of panel clamps that secure an array of PV panels to the struts. Two sets of parallel struts may be used, typically perpendicular to each other.
Typically, fire codes or building codes have a requirement that a portion of the supporting roof remain clear of PV panels and other hardware so that the roof may be penetrated rapidly by a fire fighter cutting a hole. As a result, prior art installation of PV panels generally do not extend to the edge of a roof, but rather leave a substantial gap between an edge of the panel array and each edge of a roof. Such a gap significantly reduces total available panel area.
Prior art photovoltaic mounting systems consist of two orthogonal sets of support struts. Typically the lower set, attached to the surface of a sloped roof, is aligned with the roof's structural members, such as joists. The upper set of struts, mounted orthogonally on the lower struts, are spaced such that perimeters of photovoltaic (PV) panels mount easily. Such an arrangement holds the PV panels securely. As mounted, PV panels in such an array have no moving parts.